A gap or depression in the floor or calyx of a rugose coral (Rugosa). It may be formed by the absence of septa (see septum) in a particular part of the calyx.
科学参考收录了60776条科技类词条，基本涵盖了常见科技类参考文献及英语词汇的翻译，是科学学习和研究的有利工具。